Doctor Who: Rachael Stirling reveals the strange way Mark Gatiss cast her for the show

Stirling says she was asked to appear in Doctor Who alongside her mother Dame Diana Rigg in the middle of a live play

Rachael Stirling has revealed that she received her Doctor Who casting call while in the middle of a scene in a live theatre performance with Mark Gatiss.

Stirling, the daughter of Dame Diana Rigg, was starring with sometime Who writer Gatiss in a production of George Farquhar’s 1706 play The Recruiting Officer at the beginning of last year when they both had to appear on stage pretending to have a conversation in the background.

But instead of saying “rhubarb rhubarb", as is the supposed form on these occasions, Gatiss (who was playing villainous Captain Brazen) propositioned Stirling for the role in his upcoming Doctor Who episode The Crimson Horror, which aired earlier this year.

She told RadioTimes.com: “It was hilarious. We had to sit at the back and he had an enormous ginger wig and these painted Aunt Sally cheeks, as did I with this huge canary dress and I had a fan.

“But he said to me [putting on a posh voice] ‘Have you ever been in Doctor Who?’ and I said ‘No!’ And he said ‘If I wrote one for you would you be interested?’ And I said I would and it started from there.”

Stirling was eventually cast in the drama as the daughter of her real-life mother, Dame Diana – the first time the pair had appeared together on screen.